joe brown, technology editor at "wired," amateur photographer, professional critic, knows exactly how best to capture that moment. >> people are getting better, which is nice because my facebook feed doesn't look so terrible anymore. >> reporter: the most common mistake? >> using the flash. like, if you want to make your subject look like a vampire, by all means, shine a giant, extremely white light in their face. >> reporter: also, use those lines. turn on that grid you didn't even know was there. straighten things up. >> nothing kills a photograph more than it being crooked. >> reporter: and be mindful of composition. place your subjects along those grid lines and its intersections. professionals call it the rule of thirds. and finally, be alive to the moments around you. freeze some beauty. capture what used to be gone in an instant, but now lingers, alive, in photographer nation. and the 4.4 trillion photographs that now exist to tell your story. john donvan, abc news, new york. >> thanks to john for a pretty good photography course. you can share them on flickr. go to abcnews.com